Organic LED elements include an organic light emitting layer. There is a bottom emission type or a double-side emission type that extracts light, which is generated by an organic light emitting layer, outside from a transparent substrate, in organic LED elements.
The amount of light that can be extracted to the outside from organic LED element is not more than 20% of the light emission at present.
Therefore, there is a document that describes improving light extraction efficiency by providing a scattering layer comprising a glass material in an organic LED element (Patent Document 1).